Method and apparatus for producing plaster-board.



D. E. ROBERTS.

METHbD AND APPARATUS FOR PRODUCING PLASTER BOARD.

APPLICATION'JILED MAY 20. 1909.

1,16%,103, Patented Nov. 30, 1915.

v D. E. ROBERTS. METHOD AND APPARATUS FOR PRODUCING PLASTER BOARD.

. APPLICATION FILED MAY 20, I909- 1,182,103, Patented Nov. 30, 1915.

8 SHEETS-SHEET 2.

D. E. ROBERTS. METHOD ANDAPPARATUS FOR PRODUCING PLASTER BOARD.

APPLICATION FILED MAY 20. I909.

Patented Nov. 30, 1915.

8 SHEETS-SHEET 3- AAAAAAAA/Al I ll Ewedar fi D'. E. ROBERTS.

METHOD AND APPARATUS FOR PRODUCiNG PLASTER BOARD.

APPLICATION FILED MAY 20. 1909.

L162l03. Patented Nov. 30, 1915.

. 8 SHEETSSHEET 4 N J um Q U\ Q q 3 Q 0 Q B M) D. E. ROBERTS.

METHOD AND APPARATUS FOR PRODUCING PLASTER BOARD.

APPLICATION FILED MAY 20. I909. 1,162,103. Patented Nov. 30, 1915.

8 SHEETSSHEET 5. x A J u; q -o m b i N METHOD} 0. E. ROBERTS.

Patented Nov. 30, 1915 8 SHEETS-SHEET 6.

D .E. ROBERTS. METHOD AND APPARATUS FORPRODUCING PLASTER BOARD.

APPLICATION FILED MAY 20. I909. 1.,162J08. I Patented Nov. 30, 1915.

. x 8 SHEETSISHEET 1.

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METHOD AND APPARATUS FOR PRODUCING PLASTER BOARD.

A APPLICATION FILED MAY 20. 1909. 1,12,103.

Patented Nov. 30, 1915.

8 SHEETSSHEET 8.

UNI ITE %TA FE% ATENT @FFEQFZ.

DAVID E. ROBERTS, OF FORT DODGE, IOWA.

METHOD AND APPARATUS FOR PRODUCING PLASTER-BOARD.

Dodge, in the' county of Webster and State of Iowa, have invented a certain new and useful Method and Apparatus for Producing Plaster-Board, of which the following is a specification.

The objects of my invention are to pro vide an apparatus for producing plaster board by means of continuously operating devices in which the various operations are automatic and the various parts of the apparatus are so timed and arranged as to produce the complete plaster board without attention on the partof the operator.

A further object -.is to provideimproved means for automatically delivering the finished plaster boards from the machine to a suitable discharge 'point below the machine I and for permitting the plaster boards to dry during the time they are thus being delivered.

A further object is to provide an improved method for producing plaster board, which method may be practised wholly or partially by hand, and which will produce a plaster board of strong, durable, and inexpensive construction.

My invention consists in the construction, arrangement, and combination of the various parts of the apparatus, and also in the method of producing plaster board, whereby the objects contemplated ,are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which- Figure 1 shows a side elevation of the forward end portion of the apparatus embodying my invention. Fig. 2 shows a similar view of the rear end portion of same. Fig. 3' showsa top or plan view of the forward end portion of the apparatus embodying my invention. Fig. 4 shows a top or plan view of the rear end portion of same. Fig. 5 shows a vertical, central, sectional view of the forward portion of the apparatus emter boards from the plaster board 'making device to a point of discharge below the Patented N0... so, 1915.

Application filed May 20, 1909. Serial No. 497,359.

plaster board making device. Fig. 8shows a detail, sectional view illustrating the cutting mechanism and the means for delivering the pallets. Fig. 9 shows a detail, sec-- tlonal view through the machine frame to lllustrate the means for laying strands of twine transversely relative to the moving platform. Fig. 10 shows a detail view of one of the twine engaging. and twine cutting devices, and Fig. 11 shows a perspective view of the stationary trip arm for engagng the twine cutting device.

Referring to the accompanying drawings I have used the reference numeral 10 to in dicate the main frame of the apparatus. At

the forward end thereof is a roller 11 to receive a roll of paper 12. A roller 13 is provided above the roll of paper.12 over which the paper web may be extended to the top of the machine where the plaster board is made. In front of the roller 13 is a small platform 14 on which are mounted a series of spools of twine 15, the twine from each spool being extended rearwardly on top of the paper web, the arrangement of the twine within the plaster board being illustrated in Fig. 6.

The means for supporting the plaster board during the process of manufacture comprises a shaft .16 near the rear end of the main frame having thereon a series of radial arms 17 with transverse'rods 18 at the outer ends of said radial arms. A sprocket wheel 19 is mounted on the shaft 16 and is driven by the sprocketchain 20 in the mannerhereinafter described. Atfthe forward end of the machine frame is a shaft 21 also having radial arms 22 and cross rods 23.

The conveyor on which the plaster board is .formed consists of a series of plates 2 1 of substantially the same sizeand shape as the plaster boards to be made, which plates are pivotally connected at their adjacent edges by means of the hinges 25, and each plate. is of such length that the plates will pass over the rods 18 and 23 after the manner of sprocket chains on'sprocket wheels, the said rods being designed to fit against the hinges 25, as clearly shown in Fig. 5.

chine.

when they are passing forwardly near the bottom of the machine, I have provided a series of idler shafts 28 near the bottom of the machine on which the sprocket wheels 29 are mounted and over which the sprocket plaster delivered by the belts 38 and 43 and chains 30 are passed. The said plates 24 are designed to rest on'the upper portion of said sprocket chains 30 -when traveling forwardly near the bottom of the machine. The said rails 27 extend rearwardly to a point. a slight distance in advance of the point where the plates 24 begin to move downwardly over the rear plate-supporting device consisting of the arms 17 and the rods 18. The said sprocket chains 30 at the bottom of the machine are driven from the supply pipe 41 having one or 45 shaft 31 near the rear of the machine by means of' a sprocket gearing device 32, which is drivenin a manner to be hereinafter described.

Assumingthat the sheet of paper and the twine are being moved jointly toward the rear of the machine and on top of the plates 24, I place the layer of plaster on the paper and surrounding the twine by means of the following mechanism: Arranged above the forward end of the main frame 10 is a supplemental frame 33 having at its forward, upper portion a hopper 34 having openings 35 in its bottom and containing a screw conveyer 36. 1 This screw conveyer is operatedby means of a sprocket'device 37 at one end, and means not shown are provided for feeding plaster into the hopper. Below the hopper and in position to receive the discharge from the openings 35 is an endless belt 38,

which belt is passed around two rollers 39 and 40 on the frame 33, the upper portion of said b'elt being arranged below the openings 35. Arranged above the belt 38 is a water more nozzles 42 for delivering wateron to 'of the belt 38 in advance of the position w ere the plaster is delivered. Arranged above the rear portion of the belt 38 is a second endless belt 43 passed around the rollers 44 and 45 and having its lower portion adjacent to the upper portion of the belt 38. The roller 44 is driven in unison with the roller 39 by means of the pinions '46 and 47 on the rollers 44 and 39, said pinions being in mesh with each other. Arranged midway between the rollers 39 and 40 is a smaller roller 48 to engage the upper po'rtionof the belt 38, and between the rollers 48 and 39 is a series of small rollers 49 to engage the belt 38, and between the rollers 44 and 45 is another series of'small rollers 50 to engage the lower portion of the belt 43. By this means, the

plaster and water admitted between the belts 38 and 43 will be pressed out into a smooth, fiat layer and the water and plaster In order to support the plates 24 will be commingled. In this connection, I provide for preventing the material from adhering tothe belts 38 and 43 by making the lower pinion 47 slightly larger than the ing device: Mounted upon the frame 33 below the delivery portions of the belts 38 and 43 are two large cylinders 51 and 52 rotatably mounted on the shafts 53 and 54 and arranged transversely of the machine in nearly the same horizontal plane so'that ma- .terial delivered by the belts 38 and 43 will drop between said cylinders. Passed around the cylinder 51 is an endless belt 55 which also passes around a small roller 56 arranged adjacent to the top of'the machine where the plaster board is being made, and adjacent to the roller,56 is a second roller 57, and a belt 58 is passed around the roller 57 and the cylinder 52. These belts at the point between the cylinders 51 and 52 form the sides of a hopper for receiving the plaster. The ends of this hopper are preferably formedby means of two flat disks 59 rotatably. mounted on the frame, each having one of its flat faces adjacent to the edges of said belts 55 and 58 so that said disks tend to close the ends of the hopper which is formed by the belts and the disks. By having said disks rotatably mounted they will be constantly cleaned by the action of the belts and the plaster will not adhere to them, and a relatively tight joint will be provided between the disks and the edges of the belts.

In order to applyuniform pressure to the material betweenthe belts 55 and 58, I have provided a series of idler rollers 6Q to engage the belt 55 and another series of idler rollers 61 to engage the belt 58. I have provided for operating the rollers 56 and 57 by means of the pinions 62 and 63 fixed respectively to said rollers and in mesh with each other.- The pinion 63 is made smaller than 1 the pinion 62 so that the belt 58 will move slightly faster than the belt 55 to prevent the material from adhering to it. .I have also provided additional means for preventing the material from adhering tothe belts as follows: Extended across the machine frame adjacent'to each of the rollers 56-and 57 is a stationary scraper blade 64 so positioned as to scrape off any material adhering to the belt after the belt has ,turned partially around the adjacentroller; By this means a uniform layer of plaster in a moist condition will be placed on top of the web of paper and the twine.

I use, in connection with this apparatus, a

series of detachable pallets on which the plaster board is made and on which it is retained until dry enough to support its own weight. These pallets are simply flat, rectangular boards 65 of substantially the same size and shape as the plates 24, and they are placed in position by hand between the plates 24' and the layer of paper atthe front end of the machine.

In order to press the plaster firmly around the twine and to press it tightly against the layer of paper and also to smooth off the top of it, I have provided the following mechanism: Arranged on top of the machine frame, adjacent to the point where the layer of plaster is delivered, are three rollers 66, 67 and 68, each of which is provided with a screw adjustingdevice 69 for supporting it at various POSltlOIlS of elevation relative to the tops of the pallets. An endless conveyer belt 70 is passed around the rollers 66 and 68 and the roller 67 is arranged to engage only the under portion of-the conveyer belt 70. The rollers 66 and 67-are preferably placed in horizontal alinement with each other while the roller 68 is arranged above the roller 67.- The roller 68 is driven by means of a sprocket gearing device '71 and said gearing device is so arranged that the under portion of the belt 70 will move slightly faster than the adjacent pallet so that the belt will have a troweling effect on the plaster board and will leave it smooth and uniform. By having the roller 68 elevated above the other rollers the belt is drawn away from the top of thewplaster board slowly and at an acute angle to prevent the plaster board from adhering to it. The two rollers 66 and 67 serve the purpose of forcing the layer of plastic firmly. down between the strands of twine and against the paper to firmly unite said parts.

I have provided for finishing off the surface of the plaster board by'means of a layer of combined cement and asbestos in powdered or granular form, which material is delivered in a smooth layer in dry condition on top of the wet plaster board and is firmly pressed into the wet plaster board to thereby form a relatively hard, smooth, and fireresisting surface for the plaster board. This is accomplished as follows: In the rear of the roller 68 is an auxiliary frame 72 having a hopper73 at its top provided with openings 74. In this hopper is a screw conveyer 75 driven by means of a sprocket gearing device 76,-and the dry cement and asbestos sand is placed in said hopper and delivered by said screw conveyer to the openings 74: where it is discharged downwardly. Arranged onopposite sides of the hopper 73 and below it are two large cylinders 77 and 78. Below the cylinders 77 and 78 are the rollers 79 and 80 and 'an endless belt 81 is passed around the cylinder 77 and the roller I 79 and another endless belt 82 is passed the belts, form a hopper in which the material from the screw conveyer 75 is delivered, and the rollers 79 and 80 will form this material into a smooth and uniform layer which is deposited on top of the wet plaster board. In order to firmly press this dry material into the wet plaster board, 1 have provided a second series of rollers and smoothing belts similar in constructionand operation to the rollers 66, 67 and 68, and the belt 70 before described. This second set of rollers is illustrated in Fig. 2 and is indicated generally by the reference numeral 85, and it is believed that a detail description of 'it is unnecessary. After the plaster board moves rearwardly beyond the device 85, the cement and asbestos sand will be firmly pressed into the wet plaster and enough moisture will be absorbed by the cement to cause it to unite with the asbestos sand and the wet plaster and form a smooth, hard, and uniform surface.

In order to provide for forming the side edges of the plaster-boards in a smooth and uniform manner, I have provided edge forming devices as follows: The edge-form ing device on each side of the machine is the same, and hence but one is herein specifically described. Mounted adjacent to the rear end of the device 85 are two uprightshafts, 86 having sprocket wheels 87 at their upper ends. is an upright idler shaft 88 also having a sprocket wheel at its upper end. A sprocket chain 89 is passed around said sprocket counter-shaft 92, and the cog wheels 93, one a. of which is fixed to the power shaft 94. I

have provided for driving the plaster board smoothing device 85 from the shaft 92 by means of the sprocket gearing device 95, and the main conveyer that supports the pallets is driven by means of the sprocket gearing'device 20 from the shaft 9%.

I provide means for automatically cutting ofi' the plaster boards between the edges of the pallets on which they are resting at the At the forward end of the machine The &

the sides of the machine frame are two guide rollers 96, upon which is slidingly supported a frame 97' capable of'movement longitudinally of the machine frame. Mounted in the frame 97 is a slide-bar 98 capable of movement transversely of the machine frame, and

' on this slide-bar 98 is a series of circular saws 99 arranged transversely of the machine frame in line with each other. Mounted on the frame 97 is an electric motor 100 v and this motor is provided with abelt 101 limit of movement which is passed over pulleys 102 on the saw' shafts and under pulleys 103 below the saw shafts. It is also passed over a pulley 104 on the stationary frame 97, the arrangement being such that the motor will rotate the saws and the belt will be kept tight, no matter in what position the slide-bar 98 may be.

I have provided means for moving the frame 97 rearwardly in unison with the movement of the plates 24 as follows: Mounted on the power shaft is a cam 105, and pivoted to the main frame below the cam is a lever 106 normally held forwardly by a spring 107 and provided with a roller 108 to engage the cam. At the upper end "of the lever 106 is an arm 109 pivotally connected and extended rearwardly and pivoted tothe frame 97. The plates 24 are geared directly to the power shaft and the cam 105 is so shaped and arranged that it will move the frame 97 rearwardly at the sametime and at'the same speedas the plates 24: move rearwardly, and the said saws are so arranged on the frame 97 that they will stand, during their rearward movement, in position directly over the space or joint between two of the plates 24. Then as soon as the frame 97 moves rearwardly to its limit, the spring 107-will cause the frame 97 to quickly return to its forward so that. it may again move rearwardly with the saws in position over the next adjacent plate24.

I have also provided means whereby the slide-bar 98 together with the saws will be I i moved transversely of the machine frame during the time that theframe 97 is moving rearwardly, as follows: Pivoted to the slide-bar 98 is a guide device 110 mounted upon a guide rail 111 which extends rearwardly and laterally from the machine frame and which is .fixed to the machine frame. By this arrangement, it is obvious that as the frame 97 moves rearwardly, the slide-bar 98 will move upwardly away from the main frame, and When the frame 97 moves forwardly, the slide-bar will be returned.

Y The means whereby the saws are moved 'moving rearwardly. S'lWS Wlll engage the plaster board directly downwardly at the beginning of their operative movement is as follows: The said slide-bar 98 is mounted in the frame 97 in the slots 112 so that it may be moved verti- I cally a limited distance. Pivoted t0 the frame 97 at each end, above the slot 112, is a hanger arm 113 having a shoulder 11% at itslower end designed to normally stand under the end of the slide-bar 98 and to; hold said slide-bar in an elevated position. Pivoted to thehanger arm 113 is a pawl 115 which extends toward the front of the machine. 'Fixed to the main frame of the machine is an arm 116 in position to be engaged by the pawl 115 when the frame 97 is at its forward limit of movement. Mounted on the main frame some distance in the rear of the arm 116 is a stationary arm 117 having a V-shaped arm 118 pivoted to its upper end. This arm is provided with two rollers 119 and 120 and it is so arranged that when the slide-bar'98 reaches its rearward limit of movement, it will first strike the roller 119 and then the roller 120 and carry the arm 118 rearwardly and upwardly thus elevating the slide-bar 98 far enough to permit the hanger arm 113 to drop by gravity to position with its extension 114 under the end of the slide-bar 98 to thereby hold it in its elevated, position during the forward movement of theframe 97, and when said frame 97 reaches its forward limit of movement, the pawl 115 will engage the arm 116, and hence the first operation that will take place upon the rearward movement of the frame 97 will be the withdrawal of the extension 113 of the hanger from beneath the slide-bar 98 to thereby permit the slide-bar 98 to drop down to position with the saws in engagement with the plaster board, and, as they are being constantly rotated, they will cut through the plaster board during the'time that the frame 97 is As before stated, the

above the jointv between two of the pallets and they will do this at the time when the rear pallet begins to tilt downwardly and the crack between the two pallets is thereby enlarged to permit the saws to freely pass through the plaster board.

After the plaster boards have been severed in the manner before described, the pallets together with the plaster boards will move rearwardly upon a Set of rollers 121' in the rear of the main conveyer, and each board will stand on said rollers until it is pushed beyond them by means of the next succeeding plaster board and pallet. In order to positively move the pallets with the plaster boards thereon from the platform to the set of rollers 121, I have provided the following mechanism: The outer surface of each of the plates on the platform is provided with two longitudinal means til the plaster boards can set sufficiently to be handled, and also for delivering the plaster boards and pallets to a table or truck as follows: On opposite sides of the rear end of the main frame beyond the rollers 121 are two upright frames, one on each side of the main frame, each of said upright frames comprising side rails 122 having at their upper ends a shaft 123 and at their lower ends a shaft 124. On the upper shaft are two sprocket wheels 125 and on the lower shaft are two sprocketwheels 126. Sprocket chains 127 are passed around these sprocket wheels'and a number of pallet-supporting devices are carried by these sprocket chains. These sprocket supporting devices each comprise an. angle bar 128 connected to'said sprocket chains and arranged horizontally, as clearly shown in Fig. 7. On each of the shafts 123 is a worm' gear 129 and extended transversely of the machine in the rear of the sprocket devices is a shaft 130 having a worm 131 on each end in mesh with the worm wheels129. The shaft 130 is driven by means of a sprocket wheel 132 which is connected by a sprocket gearing device 133 with a shaft 134. This shaft 134 is arranged to drive an endless conveyer belt 136 which extends from the rollers 121 to the shaft 134, as shown. in-Fig. 2. The operation of this delivering mechanism is as follows: The shaft 130 is geared to the main machine in such a manner .that the palletsupporting angle bars thereon will move downwardly the distance of the height of one of the. angle bars each time that a completed pallet and plaster board is delivered from the machine. The endless conveyer 136 is driven at slow speed and the parts are so arranged that a plaster board with its pallet will be discharged rearwardly from the conveyer 136 just in time to enter and be supported by the angle bars that are at the top of the device, asshown in Fig. 7., Then the next pallet and plaster board will be delivered to the next succeeding angle bars and so on. The plaster boards andtheir pallets will be retained in the delivering de vice for considerable period of time, long enough for the plaster board to set and harden sufficiently to be easily. handled. A truck or table may be placed below the delivering device'to receive the plaster boards their pallets when they are dropped nected to one of the shafts of the device 85,

which 111 turn is directly connected by gear I ing devices to the power shaft, as clearly shown in Figs. 2 and 4.

In some instances, it is desirable to provide means for placing strands of twine on the plaster boards transversely of the machine so that the finished board will have strands of twine extended both longitudinally and transversely of it. For automatically placing these transverse'strands of twine in position, I have provided the following mechanism: Mounted on the main frame, above the roller 13, is a cross piece 138 to support the shaft 139, which shaft is provided with a beveled gear wheel 141 on a shaft 142, which shaft is driven-by means of a sprocket gearing device 143 connected with the shaft 21. Fixed to this shaft 139 are three radial arms 144 on the outer end of each of which is pivoted a curved arm 145 so arranged as to form, with the arm144, a tapered opening between them. A spring 146 is provided for holding the outer end of the pivoted arm 145 toward the outer end of the pivoted arm 144. Mounted on the machine frame is a ball of twine 147, said twine beingextended through between the arms 144 and 145 andbeing yieldingly held therein. The said arms 144 rotate in a direction with their upper ends moving away from the ball of twine 147 so that the twine is carried to position extending straight over the movable platform, as shown in Fig. 9.

When in this position, it is necessary to cut off twine at one side of the moving platform and release it at the other side so that a length of twine will drop upon the movable platform.

To provide for cutting off and releasing the twine, I have pivoted to each of the arms 144, a blade 148 providedwitha spring 149 for normally holding it away from the space between the curved ends of the arms 144 and 145. Arranged in the path of travel of the. twine engaging arms, 1 have provided a stationary trip arm 150 so arranged that when the twine gripping arms are in the position shownin Fig. 9, the one at the lower left side of the figure will have the pivoted cutting blade 148 thereon engaged by the trip arm 150 to thereby cause the blade 148 to move across the space between the curved arms 144 and 145 to thereby sever the twine therein. Then as soon as the blade 148 passes the trip arm 150, the spring 149 wii return the blade to the position shown in Fig. 10;

' It is also necessary to provide some means for releasing the twine held between the arms 144 and .145 at thelower rightside of i the device, as shown in Fig. 9, and-at the same time that the twine is being severed at the other side. For this purpose I have pro vided an arm 151 fixed to the machine frame as said twine cutting and releasing device is geared to the movable platform, it is obvious that any desired number of transversely extended strands of twine/may be placed upon each plaster board.

In practical operation, I first extend the web of paper to osition under the rollers .66, 67 and 68, and I also extend the twine 1' over said sheet of paper and under said rollers. I then. start the power shaft of the machine in any ordinary way and begin the delivery of the plaster and the asbestos sand on top of the paper web. Theoperation of the plaster spreading and smoothing and pressing devices ticularly described, as hasalso been the operation of the means for applying the asbestos sand and cement. The operator places the pallets in position under the web as fast as erator removes the complete boards from the delivery device. All of the other operations of the machine are automatic and need no attention by the operator.

In practising the improved method of making plaster boards, which forms part of my invention, I first provide a 'web'of ma terial such as paper, then extend a number ofstrands of twine across it, then place a layer of plaster on top of the paper and surrounding the strands of twine, and finally place a layer of asbestos sand, or similar material, and cement on top of the plaster and in dry condition, and I finally compress and roll the sand into theplaster and make a smooth finish; I It is obvious that this method may be practised by the use of the machine described or either wholly or partly by hand.

I claim as my invention.

1. In a device of the class described, the combination of a frame, a platform for supporting plaster board,'comprising a series of flat plates, each being of the size and shape of a complete plaster board, saidplates being hinged together, means for supporting and moving -the plates, transverse rollers above the plates in a plane parallel therewith, a similar roller in a plane slightly 1 above the plane of the first rollers and to the rear thereof, an endless conveyer designed to travel around all of said rollers, means for driving said endless conveyer at a speed has all been heretofore parthey are needed and another' op- 1,1e2,1os

slightly faster than said platform for pressing the plaster board material down toward the plates and troweling the upper surface thereof, and means for feeding plaster board material to the plates.

2. In a device of the class described, the combination of a frame, two horizontally arranged shafts, a device mounted on each shaft comprising a series of rods arranged in a circle, said rods being parallel with the shaft, arseries of flat plates, each'of the size and shape of a plaster board, said plates being hinged together to form an endless conveyer, and said arts being so arranged that the rods will engage with said hinges, means for feeding plaster board -m-aking m'terial to said plates, means for supp'ortin the upper portion of said endless conveyer agalnst downward movement,

transverse rollers'above the plate in a plane parallel therewith, a similar roller in a-plane slightly above that of the said first'rollers and to the rear thereof, said rollers being arranged to engage the top of each plate and to press material downwardly against the plate, an endless conveyer designed to travel around all of said rollers, and means for .driving said rollers and conveyer slightly faster than said plates.

3. In a device of the class described, the combination of a frame, two horizontally arranged shafts, a device mounted on each shaft comprising a series of rods arranged in a circle, said rods being-parallelwith the shaft, a series of fiat plates, each of the size and shape of a plaster board, said plates being hinged together to form an endless conveyer, and said parts being so arra/nged that the rods will engage with said hinges, means for feeding plaster board making material to said plates, means for supporting the upper portion of said endless conveyer against downward movement, above the plate in a plane parallel therewith, a similar roller in. a plane slightly above that of the said first rollers and to the rear thereof, said rollers being arranged to engage the top of each plate and to press material downwardly against the plate, an endless conveyer designed to travel around all of said rollers, means for adjusting the distance between the said first rollers and the plates, means for adjusting the difference of elevation between the first and second set of rollers, and means for driving said rollers and conveyer slightly faster than said plates.

4. In a device of the class described, the combination of an endless conveyer, means for continuously moving it, means for supporting a paper web to extend over the upper portion 'of said conveyer to move in unison therewith,a twine holder designed to feed twine longitudinally upon said paper web, a second twine supporting device, means for unwinding twine from. the second twine suptransverse rollers porting device andvfor extending it trans-f versely of the movable conveyer, and means for cutting o'if lengths of twine and depositing them-on the top of the moving paper web.

of the paper web and forming the twine integral therewith.

6. In a device of the class, described, the

combination of an endless conveyer, means for continuously moving it, means for supporting a paper web to extend over-the upper portion of said conveyer to move -1Il unison therewith, a twine holder designed to feed twine longitudinally upon said paper web, a second twine supporting device,

means for unwinding twine from the second twine supporting device and for extending it transversely of the movable conveyer, means for cutting off lengths of twine and depositing them on the top of the moving paper web, and means for applying a continuous layer of plastic material on top of the paper web and forming the twine integral therewith, and means for compressing and troweling the plastic material on said paper web, said'means comprising a number of transverse rollers in a plane slightly above said conveyer, a transverse roller slightly above the first of said rollers and to the rear thereof, and a continuous conveyer designed to travel about all of said rollers at a speed slightly faster than -that of the plastic material.

7. In a device of the, class described, the combination of an endless conveyer, means for continuously moving it, means for supporting a paper web to extend over the upper portion of said conveyer to move in unison therewith, a twine holder designed to feed twine longitudinally upon said paper web, a second twine supporting device, means for unwinding twine from the second twine supporting device and for extending it transversely of the movable conveyer, means for cutting off lengths of twine 5. In a device of the class described, thecombmation of an endless conveyer, means and depositing them on the top of the moving paper web, means for applying a continuous layer of plastic material on top of thepaper web and forming the twine integral therewith, means for compressing and troweling the said plastic material, means for continuously applying a layer of material on top; ofthe plastic material, and means for pressing and smoothing the top surface of the second ap lied material.

8. In a-device of the class described, the combination of an endless conveyer, means for continuously moving it, means for supporting a paper web to extend over the upper portion of said conveyer to move in unison therewith, a twine holder designed to feed twinelongitudinally upon'said paper web, a second twine supporting device, means for unwinding twine from the second twine supporting device and for extendingit transversely of the movable conveyer, means for cutting off lengths of twine and deposit ing them on the top of the moving paper web,'mea ns for applying a continuous layer of plastic material on top of the paper web and formingthe twine integral therewith, means for compressing and troweling the said plastic material, means for continuously applying alayer of material on top of the plastic material, meansfor pressing and smoothing the top surface of the second applied material, and -means for automatically cutting the saidmateri'al into sections.

9. In a device of the classdescribed, the combinationof a frame, a platform for supporting plaster board, comprising a series of flat plates, each being of the size and shape of a complete plaster board, said plates being hinged together, means for supporting and moving the plates, transverse rollers above the plates in a plane parallel therewith, a similar roller in a plane slightly above'the plane of the first rollers and to the rear thereof, an endless conveyer designed to travel around all of said rollers, means for driving said endless conveyer at a speed slightly faster than said platform for pressing the plaster board material down toward the plates and troweling the upper surface thereof, means for feeding plaster board material to the plates, means for adjusting the distance between the said first rollers and the plates, and means for adjusting the difference in elevation between the first and second described rollers.

' Des Moines, Iowa, May 5, 1909.

DAVID E. ROBERTS. Witnesses: MILDRED B. GOLDIZEN, NELLIE M. TAYLOR. 

